An artificial reality system, such as a head-mounted display (HMD) or heads-up display (HUD) system, generally includes a near-eye display system in the form of a headset or a pair of glasses and configured to present content to a user via an electronic or optic display within, for example, about 10-20 mm in front of the user's eyes. The near-eye display system may display virtual objects or combine images of real objects with virtual objects, as in virtual reality (VR), augmented reality (AR), or mixed reality (MR) applications. For example, in an AR system, a user may view both images of virtual objects (e.g., computer-generated images (CGIs)) and the surrounding environment by, for example, seeing through transparent display glasses or lenses (often referred to as optical see-through) or viewing displayed images of the surrounding environment captured by a camera (often referred to as video see-through).
To provide a more immersive artificial reality experience, some artificial reality systems may include an input device for receiving user inputs, such as hand and/or finger movements. Additionally or alternatively, artificial reality systems can employ eye-tracking systems that can track the user's eye (e.g., gaze direction). The artificial reality systems may then employ the gaze direction information and/or information gained from the input device to modify or generate content based on the direction in which the user is looking, thereby providing a more immersive experience for the user. Eye-tracking systems can also be used for foveated rendering, foveated compression and transmission of image data, alertness monitoring, etc.